Industrial truck.



C. E. CUCHRAN. INDUSTRIAL TRUCK. APPLICATION FILED nov. 10. ms.

Patented Mar. 19, 1918. U $HEET$-$HEET I.

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Patented Mar. 19, 1918.

3 SHEETS-SHEET 2.

I'L'IIIII'I IIIIIIJ C. E. COCHRAN.

INDUSTRIAL TRUCK. APPLICATION FILED NOV-10.1916.

Mall. 19, 1918. a SHEETSSHEET 3.

Patentvd UNITED STATES PATENT OFFICE.

CLYDE E. COCHRAN, OF CLEVELAND, OHIO, ASSIGNOR TO THE ELWELL-PARKER ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

INDUSTRIAL TRUCK.

Specification of Letters Patent.

Patented Mar. 19, 1918.

Application filed November 10, 1916. Serial No. 180,518.

To all whom it may concern: I

Be it known that I, CLYDE E. COCHRAN, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Industrial Trucks, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

This invention relates to trucks which have a propelling mechanism and a poweroperated raisable platform. Such trucks, commonly called industrial trucks, are of great use in factories, ware-houses, freight stations, etc.', being adapted to be moved by power to bring the platform beneath goods suitably supported and then have the platform raised topick up the goods with their support, the truck being then propelled to transport the load to any desired point, where it may be deposited by lowering the platform.

The object of this invention is to provide asimple, effective and powerful mechanism for raising and lowering the platform of such a truck. In its preferred form this mechanism consists of a screw connected with a platform which is supported on parallel links and a rotatable nut for the screw, which is eared directly with the armature shaft of an electric motor. This gearing preferably consists of a worm wheel rigid with the nut and a worm rigid with the armature shaft. The motor, the gearing and the screw are all mounted toswing as a unit about a horizontal axis transverse to the platform so that these parts may aocommodate themselves to the various positions 06 the platform.

A convenient embodiment of in invention is illustrated in the drawings, wherein Figure 1 is a side elevation; Flg. 2 is aplan; Fig, 3 is a view in the nature of aplan on an enlarged soaleof the motor and mechanism connecting it to the platform Fig. i is a section 1: rough the worm wheel and, the worm with t e motor shown in side elevation; Fig. 5 isa section along the axis of the screw which elevates the platform,

showing the motor in end elevation- Fig. '6 is an elevation of the brake mechanism,

horizontal flange looking toward the end of the motor casin Fig. 7 is a sectional side elevation of t e brake mechanism looking frbm the opposite direction of Fig. 4.

Referring briefly to the general construction shown, 1 indicates a front housing carrying a driving motor indicated at 2, and a battery therefor in a suitable box 3. Extending rearwardlv from the lower portion of this front housin is a low lying skeleton frame 10. Suita ly mounted on the sides of the housing are the propelling wheels 20, and carried by the rear frame are the wheels 21. The driving motor is suitably connected with the propelling Wheels 20 in any well known manner; thus, the motor may e connected by worm gearing (not shown) in the casin A with the rotary axles of the wheels. he motor is controlled by a suitable controller indicated at '3, which is provided with an operating handle 7. The steering may be accomplished in any desired manner. For example, all four wheels ma be steered, the wheels being shown in Fig. 2 as connected by a system of cross links 24 and 25, and longitudinal links 26 and 27, with a steering column 28 (Fig. 1) operated by a hand lever '29.

It is to be understood that the general construction just described may be altered as desired. In the specific embodiment shown in the drawings, the sills 10 are secured at the front to upright frame bars 11 and at the rear to an axle 12. These sills are located at some distance Within the outer. edges of the platform, and may conpleted by pads 18 and 19 rigidly connected with the uprights 11 and 13. The housing also has two uprights 14 of channel shape secured to the outer sides of the sills 10 and rising vertically at the rear end of the housing. All of the u ri hts are secured to the p ate 15 which carries the batter box. A vertical plate 16 forms a rear wal for the housing and is secured to the uprights 14. r I

The arrangement described, of sills, uprights 11 and 13, and cross pads 18 and 19, provides a box-like space in which the front axle may rise and fall. The frame is 5 preferably supported by springs 23, between nected at the upper end by a bracket 8 to the motor casing. This driving connection is simple, direct and compact, and the spring suspension relieves the truck, and its load, of jars.

30 indicates the raisable platform. This is a horizontal member connected with the sill structure by parallel links 31 and 32. There are two links 31 on the outer sides of the sills 10 and pivoted at their lower ends to bracket 33 which are secured to the sills and to the rear end of the front housing. The upper ends of these links are pivoted to brackets 34 secured to the under face of the platform. At the rear I prefer to employ one link 32 which is mounted centrally beyond the sills and pivoted at its lower end at 36 to the stationary axle of the smaller wheels, and at its upper end to the under side of the platform. These links 31 and 32 are shown as webbed for strength. They are of the same length and are parallel, so

that as the platform moves it remains al-- ways horizontal, moving upwardly and toward the front as it rises and downwardly and rearwardly as it is lowered.

The motor, gearing and screw for elevating the platform is carried within the housing 1 in the Space immediately in front of the upright osts 14 and beneath the support 15 for t e battery box. 40 designates 1 two inclined angle bars riveted at then upper ends to the posts 14 and extending downwardly and forwardly and riveted at their lower ends to one et of posts 11. Mounted on these diagonal bars 40 are bearing brackets 41. Into these brackets extend trunnions 42 carrying an oscillatin frame 44. This frame is hollow to provi e casings for the screw, for the worm wheel and for the worm, the latter portion of the casing being extended to and being rigidly connected with the motor casing 49. Accordlngly, the motor, the gearing and the screw are all pivotally mounted by the trunnions 42.

It is desirable to have the above caslng separable, to allow ready installation and access to the worm, for oiling, etc. Accordingly, I prefer to make the casing for the worm wheel and nut in two arts. he mam portion 46 of the worm w eel cas ng ma conveniently be integral with the casmg 4 for the worm, and with the casing 43, for

that ortion of the screw between the nut and p atform, as shown in Fig. 5. The proecting end of the screw is housed by a tubular casing 45 which extends from a plate 48 which is bolted to the casin 46. Suitable webs are provided to strengt cn and stiffen the parts of the casing which as shown may conveniently be made bv two castings. The trunnions 42 may be studs screwed into the casing 43.

The screw 50 is shown clearl in Fig. 5. It lies within the casings 43 an 45 and has a shank 53 extending out through a stuffing box 54 at the lower end of the casing. This shank is rovided at its lower end with a head 56 w ich is connected by a pivot pin 51 with a bracket 58 secured to the forward end of the elevating platform 30. Within the casing 46 and threaded on the screw is a nut 60 which is shown as taking its thrust against a ball bearing 61 in the casing. This nut carries at its outer edge teeth of a worm wheel. These teeth are on a ring 62 separatefrom the body of the nut but connected with it by a friction clamp consisting of a flange 64 on the nut and a ring 65, bolts 66 and nuts 68, and springs 67 compressed between the body of the nut 60 and the nuts 68. By these means suiiicient friction is maintamed at the clamp so that normally the worm teeth and the nut revolve as a unit, but slippage is possible in case of an excessive load on the platform or other abnormal condition. The separation of the teeth d body of the worm wheel also allows the teeth to be made of bronze and the body of steel, which is an advantage.

The worm for driving the worm wheel described is designated 69. It is mounted in the casing 47, and meshes with the worm teeth 62, and is connected to the shaft of the armature. As shown in Fig. 4, the thrust of the worm is taken in either direction by a double ball bearing 68, mounted in the end of the worm casing 47 The other end of the worm is connected by a suitable coupling to the armature shaft 81. This coupling is shown as consisting of a square extension on the armature shaft engaging a corresponding recess in the worm.

It will be seen from the above construction that when the armature is revolved, the worm causes the nut to revolve com aratively slowly, which more slowly pul 5 up on the screw shaft 53 to elevate the platform. Oil for the worm gearing and for the nut and crew are contained within the hollow casing, being retained therein by the stuffing box 54.

n operation the truck is usually backed to bring the platform under the goods to be carried; then the raising motor is operated, which through the gearing nut and screw described, draws up on the shank 53 and elevates the platform, swinging it u wardly and forwardly until the load is pic ed up; then the truck is driven to the desired posi tion with the load in this condition, after which the motor 49 is reversed and the platform is lowered to allow the load to descend onto a suitablesupport. The speed of the armature is preferably such that the load is quickly raised, the reduction in the gearing giving the requisite power.

Any suitable means may be employed to open the circuit to the ralsing motor automatically when the platform reaches its uppermost or lowermost position, thus preventing the motor driving too far. The slip connection in the worm wheel also protects the mechanism. As an additional protection I provide a magnetic brake which is held in idle position when the current is flowing through the raising motor, but is automatically seated by spring action whenever the current is interrupted. Accordingly, whenever the current is off the brake is on. As the current is automatically broken at the extreme positions of the platform, the operation of the raising motor is immediately stopped at these positions. The brake is located on the end of the motor casing opposite to the worm drive, and is shown particularly in Figs. 6 and 7 and will now be described.

Secured directly to the end of the motor casing is a housing formed with an annular recess to accommodate an annular Winding 71 which is in series with the mo tor. The annular portions of the housing on opposite sides of this winding form north and south poles of a magnet. 74 indicates a ring-like piece of metal which constitutes an armature for the magnet described. This armature is normally held distant from the magnet by means of springs 76 mounted in recesses in the housing and bearing against the armature ring. Suitable studs 77 carried by the housing guide the ring. Secured at intervals on the ring are segmental linings 78 of suitable braking substance.

The springs 76 tend to pressthe armature ring with the linings outwardly into contact with a disk 80 secured to the end of the armature shaft. This disk lies within a flange 79 of the housing 70. Normally the brake is held active by the springs 76, preventing the armature revolving and thus holding the platform in a definite position.

When, however the current is turned into the raising motor the windin 71 is energized and the armature 74 is drawn inwardly away fromthe disk 80 and this disk freed.

Having thus described my invention, what I c aim 1s: a

1. In a truck,- the combination of a front nut within the housing onv the screw, and

gearing between the motor and the nut.

2. In an industrial truck, the combinat1on of a front housing, a rearwardly exfor raising tending sill frame, a raisable platform over the extension of the sill frame, a battery box within the housing, an elevating motor within the housing beneath the battery box, and a raising connection between said elevating motor and the platform comprising a nut and screw geared with the armature shaft and connected to the platform.

3. In a truck of the character described, the combination of a truck frame and an elevating platform movably connected therewith, a hollow casing carried by the truck frame, ascrew and nut occupying the casing, the screw having a shank extending outside of the casing and connected with the platform, worm wheel teeth carried by the nut, a worm meshing with said teeth, and a motor the armature of which is connected with the worm, the casing described bein separable, one partlearryin a housing or a portion of the screw and or a part of the worm wheel and the worm. and the other part forming a portion of the worm wheel housing and having an extension forming a cap over the projecting end of the screw.

4. In a truck, the combination of a frame, a raisable platform, a nut and screw, one member of which is connected with the plat form, a motor for driving the other member of such connection, and an oscillating device carried by" the truck frame, said motor being mounted on said oscillating device.

5. In a truck, the combination of a frame, a raisable platform, a screw connected with the platform, a nut for the screw, a motor geared with the nut, and an oscillating rame carried by the truck frame and carrying the nut and'motor.

6. In atruck, the combination of a frame, a raisable platform carried thereby, a screw connected with the platform, a nut for the screw carrying worm teeth, a motor, a worm meshing with the Worm teeth and connected to the armature shaft of the motor, and a pivotally mounted casing carrying the nut, worm and the motor.

7. In a truck, the combination of a housing for a battery, a rearwardly extending frame, a raisable latform above said frame, a motor earned by the housing, a nut carried by the housing, gearing be-. tween the motor and nut, and a screw extending from said nut rearwardly and connected with the raisable platform, the nut,

gearing and motor being mounted to swing on a pivot as the platform rises.

8. The combination of a housing, a frame extending therefrom, a platform above the extended portion of the frame, a casing pivotallv carried in the housing, a screw within said casing, connected at its rear end to the platform, a nut within the casing engagin the screw, a motor bodily movable wit the casin and gearing between the armature sha t of the motor and the nut.

9. In an industrial truck, the combination of a front housing, a rearwardly extending sill frame therefrom, a raisable platform carried above the extension of the sill frame, a pair of bearings carried by the housing, an oscillating hollow frame having trunnions mounted in said bearings, a screwconnected with the platform and extending into the hollow frame, a nut within the hollow frame on the screw, a motor whose frame is rigidly connected with the hollow frame to move therewith, and earing connecting the armature shaft 0 the motor with the nut.

10. In a truck of the character described, the combination of a frame, a raisable platform connected therewith, a hollow casing pivotally mounted on the truck frame, a screw, the lower end of which is pivotally connected with the platform, a nut for the screw, said casing having a chamber for the screw, and a communicating chamber for the nut, a motor mounted on the casing to move therewith, and gearing between the armature shaft of the motor and the nut.

11. In a truck of the character described, the combination of a truck frame, an elevating platform, parallel links connecting them, a hollow casing pivotally carried by the truck frame, a screw and nut occupying the casing. the screw having a shank extend ing outside of the casing and connected with the platform, worm wheel teeth carried by the nut, a worm meshing with said teeth, and a motor the armature of which is connected with the worm, the casing described being separable, one art having trunnions whereby it is pivota ly mounted and carrying a housin for a portion of the screw and for a part 0 the worm wheel and the worm, and the other part forming a portion of the worm wheel housing and having an extension forming a cap over the pro:

jecting end of the screw.

12. In an industrial truck, the oombination of a front housing carryin a battery, a silllframe extending rearward iy from the housing, a raisable platform above the sill frame, parallel links connecting the platform with the sill frame, a pivotally mounted casing within the housing, a nutwithin the casing, a screw extending from said nut out of the casing diagonally downward and rearwardly and pivotally connected with the front end of the platform, and a motor adapted to rotate said nut.

13. In a raisable platform truck, the combination of a hollow casing, a nut therein, a screw connected with the platform extending into the casing and occupying the nut, a stufiing box carried by the casing and surrounding the shank of the screw, and a motor having its armature geared with the nut.

14. In a truck of the character described, the combination of a raisable platform, a separable casing, a nut carrying wormwheel teeth mounted in the casing, a worm mounted in a communicating casing and meshing with said teeth, a motor having its armature shaft connected with the worm, a screw occupying the nutand extending out of the casing and pivotally connected with the platform, and a stufling box carried by the casing and surrounding the shank of the screw.

15. In a truck of the character described, the combination of a frame, a raisable platform movably connected therewith, an oscillating casing mounted on the frame, a nut in the casing, a motor having its frame rigidly connected with the casing and its armature shaft geared with the nut, a screw occupying the nut and extendin out of the casing, and connected with t e platform, and a stuffing box carried by the casing and surrounding the shank of the screw.

16. In a truck, the combination of a truck frame, alraisable platform, parallel links connecting them, a screw connected with the platform, a nut for the screw, a motor geared with the nut, and a slip connection in such gearing. I

17. In a truck, the combination of a frame, a raisable latform, a screw connected with the p atform, a nut for the screw, a ring having worm teeth frictionally carried by the nut, and a worm for driving such worm wheel nut.

18. In a truck, the combination of a truck frame, a raisable latform, a screw connected with the p atform, a nut on the.

screw, a ring at the periphery of the nut having worm wheel teeth, an annular clamping device for frictionally clamping the rin on the nut, a worm meshin with such teet and a motor for driving t e worm.

19. The combination, with a truck frame and a raisable platform, of an oscillating frame, a motor and suitable mechanism both carried by said frame for raising the platform, and a brake for the armature bodily movable with the motor casing.

20. In a truck, the combination of a housing, a sill frame extending therefrom, a raisable platform connected with the sill frame, a screw connected with the platform, a pivotally mounted casing carried by the housing into which the screw extends, a nut for the screw within the casing, a motor having its armature geared with the nut,

said motor bein carried b the casing to move bodily, an

a magnetlo brake carried by the motor casing and bodily movable therewith and adapted to stop the rotation of the armature.

In testimony whereof, I hereunto aifix my signature.

CLYDE E. COCHRAN. 

